1. Field of the Invention
The invention disclosed relates to current transformers.
2. Discussion of the Related Art
Current transformers (CTs) are commonly used for monitoring the current in a primary current carrying wire, by measuring with an ammeter or similar device, the induced secondary current in the transformer's sensor coil. An ideal current transformer would deliver to its sensor coil a perfectly accurate ratio of current applied to the primary current carrying wire, enabling the use of a simple ammeter or similar device for measurement. Unfortunately, magnetic losses in the core material of the transformer lead to varying degrees of accuracy. An accurate current transformer with low loss core materials is quite expensive, because of the extensive sampling and testing of the core material that contributes to the accuracy. If a designer were to choose a relatively lower accuracy current transformer for an application, any advantage accruing from a lower cost device will be outweighed by the cost of additional circuitry that must be used in the designer's application, to correct for the lower accuracy. The designer's application will need to include calibration to compensate for a low accuracy transformer's performance characteristics.